Why eight hours a night isn’t enough, according to a leading sleep scientist

What makes sleep so essential for our wellbeing comes down to three main things: to save our energy, to help our cells recover, and to help us process and understand our environment. In order to get a healthy eight hours of sleep, which is the amount that many people need, you need to be in bed for 8.5 hours. The standard in the literature is that healthy sleepers spend more than 90% of the time in bed asleep, so if you’re in bed for eight hours, a healthy sleeper might actually sleep for only about 7.2 hours.